EPGP is a collaborative effort of 13 clinical centers across the United States.

Four sites began enrolling patients and controls on November 1, 2007: Children's Hospital of Philadelphia, New York University, University of Alabama, and University of California, San Francisco. The other nine sites begin enrolling patients on May 1, 2008.
Please click here to enter your information and contact a clinical center near you.
| University |
City |
State |
| Baylor College of Medicine |
Houston |
TX |
| Children's Hospital of Philadelphia |
Philadelphia |
PA |
| Cincinnati Children's Hospital Medical Center |
Cincinnati |
OH |
| The Albert Einstein College of Medicine |
Bronx |
NY |
| Emory School of Medicine |
Atlanta |
GA |
| Johns Hopkins School of Medicine |
Baltimore |
MD |
| Mayo Clinic College of Medicine |
Rochester |
MN |
| New York University School of Medicine |
New York |
NY |
| Rush University Medical Center |
Chicago |
IL |
| St. Barnabas Medical Center |
West Orange |
NJ |
| University of Alabama at Birmingham School of Medicine |
Birmingham |
AL |
| University of California, San Francisco |
San Francisco |
CA |
| University of Michigan |
Ann Arbor |
MI |